1. Field of the Invention
The present invention generally relates to storage racks (e.g., cabinets) for computing devices such as servers, and more particularly to adjustable rail assemblies for storage racks that can accommodate differing front to rear pillar spacing among storage racks.
2. Relevant Background
Servers and other computing devices are often stored in cabinets or racks. Each of these cabinets or racks may contain numerous servers in a stacked or side-by-side arrangement. For example, a server cabinet may house 5 to 10 servers behind each door. It is desirable for each server to be installed and/or serviced without affecting operation of the other servers, and, in many cases, it is desirable for each server to be maintained or accessed without disconnecting it from power or communications/network links (e.g., to provide hot swappable and maintainable servers in an enterprise or data center environment).
To this end, each server is typically mounted within the cabinet or storage rack using a rail, slide or rack-mount kit. A rail kit typically includes a pair of outer rail assemblies, each of which is attached to front and rear vertical support members or pillars (e.g., Radio Electronics Television Manufacturers Association (“RETMA”) rails) of the storage rack frame and extends horizontally to define a server mounting location within the storage rack or cabinet. Generally, a storage rack includes a pair of front pillars adjacent a front door or opening of the storage rack and a pair of rear pillars spaced from the front pillars, where a rear door or opening of the storage rack is typically spaced from the rear pillars (e.g., so that a space or gap exists between the rear door/opening and the rear pillars of the storage rack).
Each outer rail assembly is often mated with or otherwise interconnected with a middle rail or middle member of the rail kit, where the middle rail is supported within an inner channel or groove of the outer rail assembly and may be positioned by sliding within the outer rail assembly between retracted and extended positions. In the extended position, the middle rails typically extend outward from the ends of the outer rail assemblies several inches to a foot or more to allow access to an attached or supported server or other computing device. In the retracted position, the middle rail has its outer end positioned within the outer rail.
To mount a server in the rack, a pair of inner or rack rails is attached to an outer surface of a server (or other computer device) chassis, and each of the inner or rack rails is coupled with or otherwise interconnected to a corresponding one of the middle members or rails. Generally, a server is mounted within the server storage rack by extending out the middle rail, aligning the ends of the both of the inner or rack rails on the server chassis with the ends of the middle rails, and, once proper alignment is achieved on both sides, pushing on the server chassis to cause the inner rails or racks to mate or couple with the middle members or rails (e.g., in a tongue-and-groove manner) as the inner rails slide within channels or grooves of the middle member or rails. Continued pushing then causes the middle member or rail to slide within the outer rail or member from the extended position to the retracted position, which allows the storage rack door to be closed.
As the distance between the front and rear pillars often varies from rack to rack (e.g., due to dimensional tolerances), each outer rail assembly often includes a pair of sliding (e.g., telescoping, nested, etc.) rail members that are respectively configured to engage with a respective front and rear pillar of a storage rack. As an example, some existing outer rail assemblies include first and second sliding rail members having respectively first and second mounting tabs thereon, where one or more mounting pins protrude from each of the first and second mounting tabs. For instance, an operator may slide the first and second rail members relative to each other such that a distance between the first and second mounting tabs is greater than the distance between the outer surfaces of a pair of front and rear pillars. The operator may then slide the first and second rail members relative to each other such that the pins enter or snap into respective openings through the outer surfaces and the first and second mounting tabs clamp about the outer surfaces.
In some arrangements, the operator may slide the first and second rail members relative to each other such that a distance between the first and second mounting tabs is less than the distance between the inner surfaces of a pair of front and rear pillars and then slide the first and second rail members such that the pins enter respective openings through the inner surfaces so that the first and second mounting tabs push against the inner surfaces. In either case, the operator may then fix the first and second rail members relative to each other such as by inserting threaded fasteners through aligned holes through the first and second rail members and threading nuts over ends of the fasteners. In some embodiments, the first and second rail members may be spring loaded to provide a return force that maintains the first and second rail members in their clamped position about the outer surfaces of the front and rear pillars (e.g., or pressed against the inner surfaces of the front and rear pillars).